Mencarelli



March 31, 1964 E. MENCARELLI ROTARY PUMP Filed May 19. 1961 IN VE N TOR f/vza MENCA REL L ATTORN'y United States Patent 3,126,832 RQTARY PUMP Enzo Mencarelli, Via Campestre 9, Bresso, Milan, Italy Filed May 19, 1961, Ser. No. 126,365 Claims priority, application Italy June 1, 1960 6 Claims. (Cl. 103-96) This invention relates to a rotary pump and, more specifically, to a self-priming pump (liquid ring pump).

At the present time rotary pumps operating by suction or by centrifugal force are already known and these pumps are made up of a case or outer envelope inside of which is mounted a rotating part or motor, which divides up the case into two internal chambers, specifically, one being a suction or intake chamber and the other being a delivery chamber, each chamber being connected up to its respective inlet or feed line on one hand and supply or delivery line on the other. The seat for the rotor is constituted at the sides by two discs or diaphragms.

At the present time pumps of this type are exclusively manufactured by casting and are therefore very heavy and, as a result, very expensive. Compensating for this high cost, considering the fact that the component parts are large, they are easy to assemble, the various parts being held together around the outside, and no special considerations are required to prevent the pumps from resonating or developing undue vibration during their operation, even at relatively high speeds. Such pumps are made from cast iron or other comparatively low priced material and are therefore advantageous enough for relatively large installations where, once mounted in place, it is no longer necessary to move them.

However, the chemical and food processing industries require the use of more expensive materials, such as stainless steel and other metals or alloys which are corrosion-resistant; then the cost of such pumps becomes excessive.

Furthermore, such pumps are somewhat bulky, occupying considerable space and, even though of simple design, their assembly is a laborious matter due to the heavy weight of the various parts.

The object of this invention is to do away with the above disadvantages by making a pump out of pressed elements, such components being much lighter than castings. Furthermore, since the thickness of such pressed components is much less than corresponding castings, these pumps, for overall dimensions equal to those of a pump produced by casting, will give a much larger useful area, or, for equal performance, they will occupy much less space. Furthermore, the total cost of the material will be much less and the various parts will be much easier to handle.

Another object of this invention is to provide excellent stability to the unit to prevent it from resonating or developing excessive vibration, or from having its rotor displaced off center when running under continuous operation at any speed.

Another object of this invention is to make possible the rapid disassembly of parts for cleaning or overhaul.

Furthermore, the pump embodied in this invention makes it possible to polish the active surfaces or those surfaces of the various component parts coming into contact with the liquid, said polishing preventing the formation of deposits of sludge or scale on the surfaces, thereby being of considerable advantage in the chemical and food processing industries.

The rotary pump, subject of the present invention, is composed of component parts produced by stamping or pressing, including the case, the rotor and the discs or diaphragms constituting the seat for the rotor, means being provided for supporting and centering the rotor and for 3,126,832 Patented Mar. 31, 1964 connection of the various fixed parts around the outside.

Further objects and advantages of the invention will become apparent from the detailed description which follows herein in two preferred forms of its embodiment, to be treated as illustrative of and not restrictive, reference being made to the accompanying drawings, in which:

FIG. 1 is a side view showing a vertical, longitudinal cross-section taken through the axis of a pressure pump or liquid ring pump embodying the invention, equipped with a locking system for centering the parts which is independent of the motor.

FIG. 2 is a similar view of a pump embodying the invention in which the locking system is dependent on the motor.

The same reference numbers will be used in the different figures to represent corresponding parts.

In the pressure pump shown in FIG. 1, it will be seen that it includes a centering device 1 having a circular crown with supporting base 2. This crown 1 is provided with holes (not shown) about its perimeter, uniformly spaced from one another and being used to mount and center the various parts as will be described in detail below. This centering crown 1 has at both its sides a ringshaped groove 4 which acts as a seat for the edge of the outer circumference of the two discs or diaphragms 5. These discs 5 are produced by pressing so as to offer a passage 7 for the liquid. In addition these discs have a number of holes (not shown) lining up with those of the centering crown 1.

The casing or envelope of the pump is made up of two halves, 9 and 9', produced by stamping or pressing, serving, respectively as inlet and compression chambers. These half-sections are identical to one another and each has a circular bottom 10 provided at its center with a drawn cup 11 ofiering a hole 12 for passage of drive shaft 13 and a cylindrical side Wall 14 having a threaded connector 15 and 15' respectively, for connection, for example, to secrew on to suction line 16 or delivery line 16 respectively, also obtained by stamping or pressing. Cylindrical wall 14 of each casing section 9 and 9' ends in a flange 17, turned radially towards the outside and provided with a number of holes lining up with both the holes on the centering crown and those on discs or diaphragms 5. From drawn cup 11 sleeves 18, 13' are disposed toward the inside of each half of the casing 9, 9' to rest on a flange 28 of each disc 5, serving to render the unit more rigid and give added strength. These sleeves may be produced in a single piece forming part of each half of the casing or may be fixed to the casing by welding as shown at 27 in the drawing.

A thust bearing 19 supporting shaft 13 of rotor 3 is press-fitted into each of these sleeves and an intermediate bushing 20, preferably of nylon or other acid resisting material, is press-fitted into each sleeve, said bushing 26' serving as a seat for a radial mechanical seal 21, which works together with another part 22 fixed to shaft 13 of rotor 3. Hub 23 of rotor 3 is connected to drive shaft 13 in a conventional manner such as by a key, the rotor being mounted between the two discs or diaphragms 5. If the bearing 19 should be of cast iron, a lining ring of corrosion-resistant material 24 is provided inside the centering crown 1. The various parts herein described are mounted together as shown in FIG. 1, using through bolts and lock nuts. The bolts pass through the previously lined-up holes of the centering cro wn 1, the discs or diaphragms 5 and the mounting flanges 17 of the casing sections. Since the various parts have been mounted in such a way that they are fixed in place circumferentially, there is no danger of the various parts vibrating, even at relatively high speed, since the parts are light and thin. In

addition to normal operating speed, excellent operating conditions are attained when starting and stopping. As to the operation of this type of pump, it is entirely equivalent to that of a pressure pump or liquid ring pump produced by casting, except that in the former, since the volumes of the inlet and delivery chambers are greater, given the lesser thickness of the casing, greater-performance will be attainable for the same overall dimensions.

Instead of being made in a single unit, the pump may be made up of multiple units (multi-rotor pump). In such a case the same factors will come into play and be equally valid as in the above case, except that eachintermediate casing element will be a complete wall and not shaped, and will constitute at the same time a delivery chamber for the preceding unit and an inlet chamber for the following unit.

The pump shown in FIG. 2, unlike the one shown in FIG. 1, is mounted and centered directly on motor M. This pump is, in general, similar to the one in FIG. 1 and differs in the fact that the outer surface 10 of easing 9 is a complete wall and is tapered, for reasons which will be explained further on, while inner surface it) of casing is substantially flat and open at the center, having a flange 48 turned towards the inside which defines the central hole in inner surface '10 which offers a shoulder or small step 49. Drive shaft 13 extending from motor M penetrates inside the pump through this opening in the inner surface 10 of easing 9'. Inner surface 10' has been drawn in a press to define a seat 10 to be centered in respect to motor M. Hub 23 of rotor 3 is keyed to drive shaft 13. Said hub 23 of rotor 3 has a sleeve 23' which substantially covers shaft '13 insulating it from the inside of the pump and preventing said shaft from coming into contact with the liquid circulating in the pump, making it unnecessary that said shaft be of stainless steel. The sleeve 23 of hub 23 of rotor 3 passes through a bearing or seal 32 mounted so as to provide a seal, using a packing ring 31 in contact with flange 4-8. Furthermore the sleeve 23" of hub 23 has a step or shoulder 60 on which flange 37 of a disc or diaphragm 5' bears, thereby describing a seat for rotor 3 together with another disc 5, the central position of which extends in the form of a truncated cone, the smaller end of which fits against the central part of outer surface of easing 9; thereby serving as reinforcing for said outer surface 10.

The central, protruding part of disc 5 serves as a cover or to provide space for a screw 5% which fills in the hole in hub 23 of the rotor and also serves to keep the rotor 3 in place. It should be noted that the joint 61 at the point where the edges of discs 5 and 5' come together is staggered in respect to the joint 51 at the point where the casing elements 9 and 9' come together. A packing ring providing a seal between these parts is disposed therebetween. Mechanical seals 52 and 53, united to the hub 23 of the rotor, are located around the sleeve 23 of hub 23 and placed between the shoulder at of the hub and the seal 32; Ordinarily part 52 is of rubber, while part 53 is of maphite. Flange 37 of disc 5" and flange 48 of inner surface 10' support a tubular'shaped part 54. The outersur-face 1a of casing 9 has a ring-shaped flange 55 applied to it provided with holes through which may pass the extensions of tie rods 56 which hold motor M in place. At the ends of these tie rod extensions 56, which protrude beyond mounting flange 55, cap nuts 57 are screwed in place. Thus the tie rods 56 lock together the various parts making up the pump, exerting uniform pressure about its circumference, the various parts of the pump thus being locked, in a centered position and there will be no danger of the pumps developing vibration.

The pump is assembled by simply placing the various parts in the positions shown in the drawing, locking them in place by tightening down nuts 57 all the way. To partially disassemble the pump one need only loosen and remove nuts 57, after which the casing 9 and disc 5 can be taken out or removed. To continue with the disassembly' 1. A rotary pump for liquids formed with pressed sheet metal pieces having solderless parts when forming said pieces as well as when assembling same into said pump comprising a shaft having mounted thereon a rotor member, disc members disposed on each side of said rotor member, one of said disc members having an aperture centrally thereof through which said shaft passes, the peripheries of said disc members havingmeans therebe tween to substantially encompass said rotor member, a casing member defining a chamber therein disposed about and in connection with each of said disc members, one of said casing members having an opening centrally thereof coaxial with said aperture of the disc member through which said shaft passes, the other of said disc members having a central portion defining a truncated cone, the casing member disposed about this disc member having the outer surface thereof tapered inwardly and abutting against said truncated cone thereby serving as reinforcing for the outer surface, each casing member having means connecting the chamber thereof to a suction or delivery line, each casing member and disc member being formed from stamped sheet metal defining surfaces of reduced friction when the liquid being pumped engages same, and connecting means for connecting said disc members and corresponding casing members in operative position around said rotor member sothat these members can readily be disassembled for access thereto.

2. A rotary pump according to claim 1 in which said opening of the casing member has an inwardly disposed flange therearound, said aperture of the disc member about which this casing is disposed having a flange, and a tubular part disposed on the flanges of said casing mem her and disc member.

3. A rotary pump according to claim 2 in which said rotor member includes a hub having a shoulder and a sleeve substantially covering said shaft, the flange at the aperture of said disc member bearing on said shoulder thereby defining a seat for said rotor.

4. A rotary pump according to claim 2 in which the opening and the flange therearound of the casing member defines a small step, and bearing means disposed against this small step and between the inner surface of the flange and the sleeve of said hub. V

5. A rotary pump according to claim 1 in which the connection of the peripheries of the disc members is disposed in a plane parallel to but disposed from the central plane of said rotor member which is perpendicular to the axis thereof, said casing members having a connection disposed in the same plane as the central plane of the rotor member so that the connection between the casing members is offset from the connection between the periphcries of the disc members, and sealing means provided in the connection between the connection of the casing members to form a tight connection.

6. A rotary pump according to claim 1 in which said rotary pump is operatively connected to a motor, said connecting means including a ring member abutting against said outer surface, rods passing along the outer surface of said motor and said rotary pump parallel to the axis thereof and through apertures provided in said ring member, and securing means disposed on the ends of the rods to abut against said ring member and one end of said motor to maintain the motor and rotary pump in operative disposition.

References Cited in the file of this patent UNITED STATES PATENTS 6 Bower Dec. 18, 1951 Weisenbach et al Dec. 15, 1953 Lung July 10, 1956 Heinicke July 22, 1958 Zimmermann et a1. Feb. 23, 1960 FOREIGN PATENTS France Nov. 17, 1950 France Nov 15, 1957 

1. A ROTARY PUMP FOR LIQUIDS FORMED WITH PRESSED SHEET METAL PIECES HAVING SOLDERLESS PARTS WHEN FORMING SAID PIECES AS WELL AS WHEN ASSEMBLING SAME INTO SAID PUMP COMPRISING A SHAFT HAVING MOUNTED THEREON A ROTOR MEMBER, DISC MEMBERS DISPOSED ON EACH SIDE OF SAID ROTOR MEMBER, ONE OF SAID DISC MEMBERS HAVING AN APERTURE CENTRALLY THEREOF THROUGH WHICH SAID SHAFT PASSES, THE PERIPHERIES OF SAID DISC MEMBERS HAVING MEANS THEREBETWEEN TO SUBSTANTIALLY ENCOMPASS SAID ROTOR MEMBER, A CASING MEMBER DEFINING A CHAMBER THEREIN DISPOSED ABOUT AND IN CONNECTION WITH EACH OF SAID DISC MEMBERS, ONE OF SAID CASING MEMBERS HAVING AN OPENING CENTRALLY THEREOF COAXIAL WITH SAID APERTURE OF THE DISC MEMBER THROUGH WHICH SAID SHAFT PASSES, THE OTHER SAID DISC MEMBERS HAVING A CENTRAL PORTION DEFINING A TRUNCATED CONE, THE CASING MEMBER DISPOSED ABOUT THIS DISC MEMBER HAVING THE OUTER SURFACE THEREOF TAPERED INWARDLY AND ABUTTING AGAINST SAID TRUNCATED CONE THEREBY SERVING AS REINFORCING FOR THE OUTER SURFACE, EACH CASING MEMBER HAVING MEANS CONNECTING THE CHAMBER THEREOF TO A SUCTION OR DELIVERY LINE, EACH CASING MEMBER AND DISC MEMBER BEING FORMED FROM STAMPED SHEET METAL DEFINING SURFACES OF REDUCED FRICTION WHEN THE LIQUID BEING PUMPED ENGAGES SAME, AND CONNECTING MEANS FOR CONNECTING SAID DISC MEMBERS AND CORRESPONDING CASING MEMBERS IN OPERATIVE POSITION AROUND SAID ROTOR MEMBER SO THAT THESE MEMBERS CAN READILY BE DISASSEMBLED FOR ACCESS THERETO. 